The present invention relates to nozzles for dispensing viscous material from pliable containers.
A number of viscous materials are dispensed from collapsible containers where the pressure for dispensing the viscous material is generated by applying pressure to a pliable container. The shape of the material issuing from the container is determined by the cross-sectional shape of the nozzle forming the open end of such containers. The viscous material within the container flows under the influence of the pressure generated by collapsing the container toward the nozzle, and is extruded therefrom through the nozzle and its dispensing orifice. The cross-sectional shape of the extruded viscous material is determined by a cross-sectional shape of the dispensing orifice.
The prior art shows a number of nozzle orifice configurations and while most of the prior art orifices are circular, forming a cylindrical extrudate of the viscous material being dispensed, a great many different shapes have been used for nozzle orifices. See for example the interior nozzle orifices of FIGS. 4 through 7 of U.S. Pat. No. 5,823,387 to Manadanas, et al. Elongated dispensing orifices are disclosed in a number of references, including European Patent Application 01 78 377 A2.
Aside from the configuration of the dispensing orifice in a nozzle structure for dispensing a viscous material, the nozzle structure must be such that the pressure generated from collapsing the container, usually hand pressure, is sufficient to extrude an adequate amount of viscous material from the dispensing nozzle, with a shape and at a rate that is suitable for the particular application.
In addition, the nozzle structure should be capable of being formed in conventional molding apparatus with tooling that is not inordinately expensive to manufacture.
To solve these and other problems in the prior art, there is provided a nozzle for dispensing a viscous material from a source of the viscous material. The nozzle includes a dispensing orifice, a nozzle throat in flow communication with that orifice, and a transition in flow communication with the nozzle throat and the source of viscous material. The source of the viscous material is a container having an interior cross-sectional area, at the interface of the source and transition, of a value A. The transition has a cross-sectional area, at the interface with the nozzle throat, of a value B. The dispensing orifice has a cross-sectional area, in a plane perpendicular to flow through the orifice of a value C. Where the nozzle includes a generally rectangular, xe2x80x9crace track,xe2x80x9d or elliptical dispensing orifice, A is in the range of from 2 to 3 of B and B is in the range of from 25 to 35 of C.
Nozzles having such configurations are capable of dispensing viscous material in a desired shape, at acceptable rates, without excessive pressure being developed in the container. Moreover, such nozzles can be fabricated and attached to the containers in automated machinery that need not include complex tooling.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.